Motor fuel multipurpose agents



United States Patent 3,527,583 MOTOR FUEL MULTIPURPOSE AGENTS Helen I. Thayer, Oakmont, Pa., assignor to Gulf Research & Development Company, Pittsburgh, Pa., a corporation of Delaware No Drawing. Filed Apr. 25, 1966, Ser. No. 544,838 Int. Cl. C101 1/26 US. C]. 44-58 5 Claims ABSTRACT OF THE DISCLOSURE The mixture and reaction product of lecithin and certain 1,2-disubstituted imidazolines are useful as gasoline antiwear and antifilter-clogging agents.

This invention relates to multipurpose additives for motor fuels, to motor fuel compositions containing a minor proportion of said additives, and to methods of improving the performance of gasoline-burning engines with said compositions. The additives of the present invention perform two primary functions in gasoline including (1) reduction of wear in cast iron piston rings of a gasoline-burning engine and (2) reduction of the tendency of gasoline to clog a fuel filter element.

The antiwear and antifilter-clogging gasoline additives of the present invention comprise either a mixture of or the reaction product of lecithin and a 1,2-disubstituted imidazoline. The imidazoline has an alkylamine substituent in the 1-position and an alkyl substituent containing 7 to 29 carbon atoms in the 2-position. A preferred 1,2- disubstituted imidazoline of this invention is prepared by reacting diethylene triamine and a mixture of saturated and unsaturated fatty acids to produce predominantly a I-(Z-aminoethyl)-2-alkylimidazoline having the general formula In the absence of lecithin, the 1,2-disubstituted imidazolines utilized in this invention impart an only partially beneficial effect when added to gasoline. The 1,2-disubstituted imidazolines per se impart antiwear properties to gasoline as evidenced by reduction in loss of metallic iron from cast iron piston rings. However, when the 1,2-disubstituted imidazolines are either mixed with or reacted with lecithin the product exerts an additional highly beneficial effect in gasoline, i.e. substantial reduction of the tendency of the gasoline to clog the filter through which it passes in its flow to an engine. The lecithin imidazolines of this invention probably reduce filter clogging by completely dissolving some of the dispersed solids in gasoline and by partially dissolving other dispersed solids to reduce the size thereof.

The antifilter-clogging characteristic is highly important because in nearly all automobiles motor fuels are filtered during flow to an engine. Furthermore, reducing the level of solids in gasoline in itself tends to decrease wear of piston rings by reducing abrasion at said piston rings. Therefore, the antiwear and antifilter-clogging characteristics of the additives of this invention cooperate to pro duce a common advantageous effect: the antiwear function contributing directly to piston ring wear rate reduction and the antifilter-clogging function contributing indirectly 3,527,583 Patented Sept. 8, 1970 ice to reduction of engine wear by completely dissolving a portion of the potentially abrasive solids in gasoline and by partially dissolving another portion of said solids to reduce the size thereof, thereby permitting easier removal of the remaining solids by filtration.

The antifilter-clogging characteristic of both the mixture of and the reaction product of lecithin and the 1,2- disubstituted imidazolines utilized in this invention is unexpected because neither lecithin by itself nor the imidazolines by themselves impart antifilter-clogging characteristics to gasoline. On the other hand, gasoline compositions containing either the unreacted mixture of or the reaction product of lecithin and the 1,2-disubstituted imidazolines of the invention exhibit high antifilter-clogging characteristics.

It is significant that imidazolines differing from the imidazolines of the present invention only by the addition of a methyl substituent to the imidazoline ring do not exhibit antiwear properties. While the reaction product of diethylene triamine and a fatty acid produces a 1,2-disubstituted imidazoline which is a highly effective antiwear agent, the reaction product of dipropylenetriamine and the same fatty acid produces a 1,2,4 or 1,2,5-trisubs tituted imidazoline containing a methyl substituent in either the 4 or 5 position of the imidazoline ring which is not an effective antiwear agent. Therefore, while is an effective antiwear agent, the compound N CH2 CH and methyl isomers thereof are not antiwear agents. Additional comparisons of the characteristics of closely rated compounds are found in applications Ser. No. 544,839 and Ser. No. 544,840, both entitled Motor Fuel Multipurpose Agents and filed on the same date as this application by the same inventor.

The 1,2-disubstituted imidazolines of this invention have the general formula R is a saturated or unsaturated hydrocarbon radical containing 7 to 29 carbon atoms, generally, and ll to 17 carbon atoms, preferably,

R is a methylene group or an ethylene group, preferably an ethylene group, and

R and R, can be either hydrogen, methyl or ethyl radicals, but are preferably hydrogen.

A highly effective commercial imidazoline whose major component is 1- (2-aminoethyl)-2-heptadecenylimidazo is prepared by reacting a mixture of long chain fatty acids with diethylenetriarnine. Another imidazoline can be prepared by reacting a fatty acid having 8 to 30 carbon atoms with N-aminomethyl ethylenediamine. The fatty acid mixture used in the synthesis of the abovementioned commercial imidazoline comprised 37.0 percent linoleic acid, 6.0 percent conjugated linoleic acid, 52.5 percent oleic acid, 0.5 percent palmitic acid, 0.5 percent palmitoleic acid, 2.5 percent stearic acid, and 1.0 percent of other acids. Other suitable acids that can be used in the synthesis include lauric, myristic, arachidic, behenic, cerotic and lignoceric acids.

Examples of suitable 1,2-disubstituted imidazoline compounds of this invention include 1-(2-aminoethy1)- 2-undecylimidazoline, 1 (2 aminoethyl)-2-heptadecylimidazoline, 1- (2'-aminoethyl)-2-tridecylimidazoline, 1- (2-aminoethyl)-2-(8"-heptadecenyl)-imidazoline, 1 (2'- N,N dimethylaminoethyl) 2-(8",11-heptadecadienyl) imidazoline, 1 (2 N-methylaminoethyl)-2-pentadecylimidazoline and 1-aminomethyl-2-heneicosylirnidazoline.

Any commercial lecithin can be utilized in accordance with this invention, such as lecithin derived from soybean oil, corn oil, linseed oil or egg yolk.

A particular commercial lecithin which was advantageously both mixed with and reacted with an imidazoline as described above is a neutral oil solution of a filtered soybean lecithin with a moisture value less than 0.75 percent by weight, an acetone-insoluble value of 70 percent by weight and a viscosity of 3046 centipoises. According to one method of preparation of the lecithin derivative of the 1,2-disubstituted imidazolines, base lecithin is reacted with the imidazoline at 5580 C. for 19 to 55 hours while stirring the reaction mixture. In one synthesis, 15 grams of 1-(2-aminoethyl)-2-heptadecenylimidazoline and 60 grams of the commercial base lecithin were heated at 55-80 C. for 19 hours. The conditions of reaction of the base lecithin with the 1,2-disubstituted imidazoline are not critical and a wide range of reaction conditions can be utilized. In general, the reaction can be carried out at a temperature between about 40 C. and 100 C. for a time duration of about 5 to 100 hours.

The concentration of the lecithin-imidazoline derivative or the mixture of lecithin and imidazoline in gasoline is not critical. For example, an additive of this invention can be present in gasoline in a general concentration range of 0.1 to 100 pounds per 1000 barrels, or a preferred concentration range of 1 to 25 pounds per 1000 barrels. In terms of weight percentage, an additive of this invention can be present in gasoline in a general range of .00004 to .04 percent or a preferable range of .0004 to .01 percent. If the additive comprises a mixture of lecithin and imidazoline, the ratio of lecithin to imidazoline can vary widely. For example, the ratio of lecithin to imidazoline can be within the range 1:2 to 20:1, generally, or within the range 2:1 to 8:1, preferably.

The gasoline compositions of this invention contain as the hydrocarbon portion thereof any of the known gasoline hydrocarbons, such as, for example, hydrocarbons boiling in the range of about 90 to 400 or 425 F. The hydrocarbon portion of the gasoline compositions can contain normal, branched-chain, and cyclic hydrocarbons having from 4 to 12 carbon atoms. The hydrocarbon portion of the gasoline compositions can comprise products prepared in the chemical conversion of hydrocarbons to produce gasoline such as the products prepared by isomerization, alkylation, polymerization, cracking, disproportionation, hydrogenation, dehydrogenation, and combinations of such processes. A common gasoline composition contains a major proportion of the gasoline hydrocarbons prepared by fluid catalytic cracking and a minor proportion of an alkylate prepared from isobutane and C and/or C olefins. The base fuel can comprise about percent of gasoline from the fluid catalytic-cracking process, and about 20 percent of the aforementioned alkylate.

EXAMPLE 1 Radioactive piston ring wear tests were performed to demonstrate the high antiwear characteristics of a gasoline containing a compound of this invention and to also demonstrate the criticality of the chemical structure of the additives of this invention. Following is a description of the test procedure employed in the radioactive piston ring wear tests.

Test procedure Each radioactive ring wear test was performed with a CLR laboratory test, 4-stroke, single cylinder internal combustion engine equipped with a cast iron top compression ring which prior to use had been rendered radioactive by insertion into the pile of an atomic reactor. The engine provided with the radioactive ring was operated at constant speed for 10 hours under the following test conditions:

Speed: r.p.m. 2000 Load: BHP 5 Spark (before top center) 15 Air-fuel ratio 13.7/1.0 Cylinder wall temp. F. 112 Sump oil temp. F. Carburetor: intake air temp.: F. 85

During the test the motor oil accumulated particles of the radioactive metal lost by the radioactive piston ring through wear. The radioactive metal content of the motor oil was continuously counted by means of a Geiger counter and recorded. At intervals oil samples were taken and the amount of dilution of oil by fuel was determined. Since dilution of oil by fuel tends to depress the radioactivity measurement, the amount of wear was calculated on the basis of radioactivity counts corrected by a factor corresponding to the amount of dilution of the motor oil with fuel.

Table 1 shows the results of radioactive piston ring wear tests made with a gasoline sample containing 1-(2-aminoethyl)-2-heptadecenylimidazoline, which is a 1,2-disubstituted imidazoline of this invention, and with separate gasoline samples containing the imidazoline reaction products of long chain fatty acids and ethoxylated and nonethoxylated dipropylene triamine, both of which are trisubstituted rather than disubstituted imidazolines and therefore not imidazolines of this invention. As shown by the structural formulae in Table 1, the 1-(2-aminoethyl)- 2-heptadecenylimidazoline of this invention differs primarily from the reaction product of long chain fatty acids and dipropylene triamine only by the absence of a methyl group on the imidazoline ring.

TABLE l.--RADIOACTIVE PISTON RING WEAR TESTS I-(Z-aminoethyl)-2-heptadecenylimidazoline The reaction product of long chain fatty acids and dipropylene triamine The reaction product of long chain fatty acids and dipropylene triamine plus 2 mols of ethylene oxide The structural formula is (C 17) b A mixture comprising in major proportion m-g N-CH2-CHNH2 N H; CH3

(IEH C H3 and methyl isomers thereof.

0 A mixture comprising in major proportion (Cm-(l3 N-CI'IzCIINII(CIIzCH2O)2II and methyl isomers thereof, and/0r corresponding imidazolines wherein two separate hydroxyethyl groups are attached to the side chain nitrogen wear properties. Example 2 therefore reinforces the showing of eriticality of the structure of disubstituted imidazolines as compared to trisubstituted imidazolines in regard to antiwear properties.

EXAMPLE 2 TABLE 2.RADIOACTIVE PISTON RING WEAR TESTS Conccn- Control 'lestIron tration, Iron wear, wear Fuel additlve p.p.n1. Piston rings Oil gg- The reaction product of long chain fatty acids and 98.5 Radioactive Base motor oil 8.7 6.1

dlethylene tIlaIIlllle. cast iron. free of additives. The reaction product of long chain fatty acids with 98.5 ,do do 8.7

diethylene triamine and 2 mols of ethylene oxide. The reaction product of long chain fatty acids with 98 5 do .do 5.5

dipropyl ene triamine plus 2 mols of ethylene oxide. The reactlon product of long chain fatty acids and 98 5 do do dipropylene triamine. e

n A commercial mixture comprising about 90 to 95 percent by weight of 1-(2-aminoothyl)-2-heptadecenylimidazoline b A mixture containing in major proportion and/or corresponding imidazolincs having two separate hydroxyethyl groups attached to the side chain nitrogen.

a N o significant change in wear as compared to control.

d A mixture containing in major proportion and methyl isomers thereof, and or corresponding imidazolines having two separate hydroxyethyl groups attached to the side oh ain nitrogen.

l A mixture contalning in major proportion and methyl isomers thereof.

Table 1 shows that the disubstituted imidazoline of this inventionreduced the piston ring wear rate 33 percent as compared to a reference gasoline sample, while a trisubstituted imidazoline differing from the imidazoline of this invention primarily only by the addition of a methyl group to the imidazoline ring was not an antiwear agent and actually increased the piston ring wear rate by 5 percent. Table 1 also shows that the trisubstituted imidazoline can be transformed into an effective antiwear agent by adding ethylene oxide thereto, a procedure which adds considerably to the cost of the additive as compared to the nonethoxylated imidazoline of this invention. Furthermore, it is shown in Example 2, below, that the addition of ethylene oxide to the disubstituted imidazoline of this invention actually deprives .said imidazoline of its anti- CH2 CH3 C Ha A further series of tests was conducted which utilized a method other than radioactivity to determine not only antiwear characteristics but also engine cleanliness characteristics of a disubstituted imidazoline in gasoline. The (CHFC N CH2CH2NH2 antiwear tests measured the wear rate in each of the three (IJHZ piston rings of each of the six cylinders of an automobile engine. The following procedure was utilized for conduct- CH2 in the (CSlS this exam 16. b Commercial antioxidant bearing corrosion inhibitor and detergent g f p 5 comprising barium sulfonate, barium phosphonatc, zinc dialkyl dithio- Test procedure phophate andladntitrogcg-containing gonpoundt d i t d 6 mm a sun an v scosi in ex The test is performed with a 216 cu. in. 6-cylmder autoimprgven m1 6 ergen pour pom epres y mobile engine in five 8-hour test periods. Following each d ga g gg gg agentcomprisingasilwoncpolymer.

v 8 1'0 11 I1 I. of the first four periods of operation the engine is shut 1 reduction in wean down for a 4-hour interval. Preceding the first 8-h0ur i g gi 1 23 test period there is a progressive break-in over a 4-hour uc mw period in order to attain test conditions by the end of the last hour of the break-in period. At the end of the breakin period the crankcase oil is drained, the crankcase refilled and the engine operated for a 10-minute warm-up 15 before commencing the first 8-hour period of test operatier]. Table 3 shows the high utility of an additive of this Following are the conditions prevailing during the test: illvelltiofl for pq g 0f P malntalmng $181116 Clean- Load. BHP 45+1 liness and reducing piston nng wear.

The tests of Examples 4 and 5 were conducted to illus- Speed: 5 2 5 'trate the improvement imparted to gasoline by lecithin spark advance 2552 6 m mixtures with disubstituted imidazolines and lecithin de- S ark In a in :2 er rivatives of disubstituted imidazolines in regard to fuel p p g g filter-clogging characteristics. Valve clearances: 1n.:

Intake 0.008. EXAMPLE 4 Exhausf Table 4 shows the results of gasoline circulation tests Intake mamfold f 5?! locked m to determine the maximum possible throughput through off Posltlon'. a fuel filter until a 50 percent reduction in fuel flow rate Tm plated cast Iron through the filter element occurred. The tests were con- Water Jacket coolant ducted with a gasoline control sample and with gasoline temperature: containing a lecithin-free disubstituted imidazoline.

Inlet: F. 85i5. {I Outlet: F. 95:2. Oil temperature: F 155:5. Air-fuel ratio 14.5i0.5/1.0. Crankcase ventilation: c.f.m. 1. Oil change: qt. 4 /2. Crankcase lubricant Motor oil. TABLE 4.GAsoLINE CIRCULATION TESTS At the end of the test, the engine is disassembled and 40 igg g 1mmt by volumeigasolme rated visually for deposits on the following parts to es- Tetraethyl lead, rnl./gal 2.5 2.5 tablish the 5 engine cleanliness rating- Th35305"trfifittfitilg fiitettymartinat: vamlih sludge dePS1tS ot dliif ififi?it ittltlitl atmetastasis 15 Plston skll'ts 011 Screenthere is a percent reduction in flow rate through Cylinder walls Crankcase oil pan. filter 5 Crankcase Oil P Rocker-arm m ly. 40 B A commercial mixture comprising about 90 to 95 percent by weight Push-rod cover plate Rocker-arm cover plate. 0iI'Q'ammOethYD'z'heptadecenylmlidamune Rocker-arm cover plate; Push-rod cover plate. 11)- 2 z z The total engine rating is the sum of the ratings made on N Hz the ten parts listed above. Each part is rated on a scale 50 fi of 0 (heavy dePOStS) to 10 (clean) b Gasoline circulation test procedure is described in SAE Reprint No The piston rings were weighed before and after the test glg n, G. GGastoii and .1611. Thomzafsgiltgontribtitim ot sedn nen t ana itives n aso inc 0 ogging o ers in utomo ive ue ysto ascertain? the ring Welght loss The results of the test terns, presented at Philadelphia, Pennsylvania, Meetings, Oct. 29- are shown 1n Table 3. Nov. 2, 1902.

TABLE 3.EFFECT OF ADDI'IIVE ON ENGINE CLEANLI- NESS AND WEAR rdnake-up percent by volume, gasoline 100 100 8 Z Tetraethyl lead, mlJgal 2. 5 2. 5 T1110 ilclacltlontproduct ofnlaonlg1 glagiibgatty acids and 5 18 en 1111 e, S. I on m ke-11g, gmgiit b; volume; 8 2 Table 4 shows that m the absence of lecithin, a disub- Llghfi neutral 30-25 30-25 stituted imidazoline of this 1nvent1on 1s unfavorable to Medium neutral o1l 65.00 65.00 ()fladditiveb M5 M5 the filter-clogging characterisncs of gasollne.

0. 50 0. 50 0.01 0. 01 EXAMPLE 5 G-cylinder automobile engine cleanliness and wear test:

Totalenemecleflnhnessratmg(100=c1ean)(Varmsh 5 A further serles of asolme filter-clog in tests were and sludge) 0 82 0 g g g Skirt varnish 1 5611559; bi iah'zid 'iaiii III II III 63 5 71 5 q p to lllustrabte p e p z gasome in t is respect y ecit in mixtures wit an eriva- Rm wel ht loss:

i irst ring (compression), averageweight loss for tives of a disubstituted lmidazoline. These teste were con- SIX plsflmsymg 92 68 ducted with gasoline containing lecithin alone, with gaso- 34 1 70 line containing a lecithin mixture with disubstituted imidring.average'weightlossforsix pistons, 54 834 azoline and with gasoline containing a lecithin derivag tive of disubstituted imidazoline. The results of these Tta1averagerhgwcigmmss'mg tests are shown in Table 5. In reference to the data of Acommercial mixture comprising about to percent by weight ofa e 5, it is noted that a gasoline is considered [0 6X- 1'(z'ammoethyl)'z'heptadecenylimidawlm 75 hibit satisfactory filter-clogging performance when there 9 10 is less than 50 percent reduction in fuel flow rate through I claim: a filter element at 20 gallons throughput. 1. A motor fuel having antiwear and antifilter-clogging characteristics comprising gasoline and between about TABLE TGASOLINE CIRCULATION TESTS .00004 and .04 percent by weight of an agent selected Addliltivglslzi X from the group compising the reaction product and mixn B a Reaction product of lecithin and the reaction tures of lecithm and I-(Z-ammoethyl)-2-heptadeceny1- product 05 long chain fatty acids and diethylene lmldazollne. Mi l il g; X 2. A motor fuel having antiwear and antifilter-clogging 1X ure 0 Sci im a an 0 reac 1011 pro no 0 long chain acids and diethylene triamine b X characterlstlcs comprlslng galsollne and between 9 Gasoline Tests 10 .00004 and .04 percent by Weight of an agent comprising Gasoiine circumion tests percent reduction in the reaction product and the mixture of soybean lecithin flow rate at stated gallons fuel throughput (more than 50 percent reduction in flow rate at and 1 (2 ammoethyl) heptaiiecenyhmldazphne' 20 gallons fuel throughput is unsatisfactory), 2 3. A mother fuel havin anttwear and antifilter-cloggtng percent d 50 o 25 e 2 Intake system deposit test, percent reductionm characteristlcs comprising gasoline and between about carburetor-type gum deposits 46 48 e1 .00004 and .04 percent by weight of a compositton se- 11 A commercial neutral oil solution of a filtered soybean lecithin with lected from h group compr sing mixtures and reaction moisture value less than 0.75 percent by weight, an acetone-insoluble product of lcclthll'l and the lmidazoline. value of 70 percent by weight and a viscosity of 3,046 centipoises.

b A commercial mixture comprising about 90 to 95 percent by weight 3 of 1-(2-aminoethyl)-2-heptadecenylimidazoline R1CNRZN (C17)-C N-CHzCHzNH2 20 I N CH2 R4 CH CH2 2 v For the gasoline circulation tests additive concentrations were 15 lbs. Wherem per 1 000 barrels of gasoline plus 0.5 percent by volume solvent oil. Gasoline circulation test procedure is described in SAE Reprint No. 610 B, R1 15 an alkyl radical contammg 7 to 29 carbon atoms (3. E. Gaston and J. J. Thomas, Qontribution of Sediment and Addi- R is selected from the group consisting Of methylene tlvcs 1n Gasoline to Clogging of Filters in Automotive Fuel Systems, d th 1 pgegented at Philadelphia, Pennsylvania, Meetings, Oct. 29-Nov. 2, R an d R 1 d f h f 3 an 4 are se ecte rorn t e group conslstlng o d l l 11 e i ij iti f hydrogen, methyl and ethyl radicals.

I For the intake system deposit tests the concentration of additives 4 A othor f iv iw 1 was 15 lbs. per 1,000 barrels of gasoline. The test similates deposition of 30 h e1 ant F and antlfilter c oggmg gum carried by gasoline in a carburetor and involves forming a gum c aracterlstlcs compnslng gaso me and between about deposit inatest apparatus by evaporating additive containing, highgum ()()()()4 a d ()4 percent by w i ht f a iti content fuel flowing countercurrent to a stream of heated air. At the end f of the test, the weight of the adhering gum is determined and compared to lected Tom the group Compnslng mlxtures and reactlon a reference run without additive for an appraisal of the additives deterd t f lecithin d th i id li geney action. The test employs the same apparatus described by J. L.

Keller and F. S. Liggett, Induction System Gum-Engine Versus 30 R-C- -N CHQCIX NHg Bench Test, Symposium on Vapor Phase Oxidation of Gasoline, AS'IM Special Technical Publication No. 202, pp. 21-40 (1956), but a somewhat N CH;

different procedure is employed in order to appraise detergency action of additives. A gum deposit is formed on the walls of a steamjacketed glass CH U-tube by evaporating two liters of gasoline distillate admitted to the system countercurrent to a stream of preheated air. The U-tube is then wherein washed with a number of portions of naphtha until a final wash shows no 40 discoloration. The amount of gum adhering to the apparatus is then R is an alkyl adi al c tai i 7 t 29 carbon at determined by extracting with C.P. acetone and evaporating the acetone 5 l extract with filtered, heated air to obtain a gum residue which is heated A motor fuel havlng antlwear and antlfi ter'clogglng in an oven for one-half hour at 100-105 C., cooled and weighed. Results characteristics comprising gasoline and between about of runs using the same gasoline with and without additive are compared to determine detergcncy action. .00004 and .04 percent by weight of a composition coml prising the mixture of and the reaction product of soynoted above, satlsfactpry filter-c Oggmg p bean lecithin and the lmidazolme ance is achieved when there 1s less than percent reduc- (CH) C N CHQCHBNHZ tion in the fuel flow rate through a filter element at 20 [1 gallons throughput. The data in Table 4 indicate that disubstituted imidazoline without lecithin did not produce 50 CH! a gasoline composition meeting this filter-clogging per- R f ct d formance requirement. Also, Table 5 shows that lecithin e erences l e Without imidazoline did not produce a gasoline composi- UNITED STATES PATENTS tion meeting this filter-clogging performance requirement. 2,633 146 3/1953 Witt 123 136 However, Table 5 shows that both the mixture of lecithin 2,773 492 12/1956 Klemm 123 136 with disubstituted imidazoline and the lecithin derivative 2,987,527 6/1961 sincroft et a1 44 66 of disubstituted imidazoline produced a gasoline composi- 3,014,793 12/1961 weisgerber et a1 44 66 tion which easily satisfied required filter-clogging perform- 3,131,175 5/1964 Twiben 123 136 ance levels. Table 5 also shows that use of either the mix- 3,273,980 9/1966 Le Suer et a1 44 63 ture of lecithin with disubstituted imidazoline or the 3,282,836 11/1966 Miller et a1 44 63 lecithin derivative of disubstituted imidazoline resulted in reduced formation of carburetor-type gum deposits as DANIEL E, WYMAN, P i a Exami r 1 ggilpalfid to the performance of lec1th1n a one 1n this re Y. H. SMITH AS818 tan t Examiner Various changes and modifications can be made without 5 departing from the spirit of this invention or the scope thereof as defined in the following claims. 76

US. Cl. X.R.

mg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 a 527 s 583 Dated September 8 1970 Inventor(s) Helen I. Thayer It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 8, line 10, "30%" should read -37%.

Table 4, line 44, "5" should read (5-.

Column 10, claim 4 line 1, "mothor fuel haivng" should read -motor fuel having-.

Claim 5, last line, CH should read CH S'IGRED "I'D SEALED SEAL) MIMI Oifiw Aiming WIT-mu E- m. Gamiasiom of Patents 

